Phytoneuron 2012-39: 30. 2012.
Herbs, annual, acaulescent or caulescent. Stems erect, 0 or 30–50(–60) mm, glandular-puberulent. Leaves: basal densely clustered; petiole absent; blade linear, (6–)8–35 × 1–4.5(–9) mm, margins entire, plane, proximal 1/2+ ciliate, apex obtuse, surfaces glabrous. Pedicels 0–2 mm in fruit. Flowers 1 per node, chasmogamous. Calyces slightly asymmetrically attached to pedicel, inflated in fruit, (5–)7–15 mm, pilose, lobes subequal, apex obtuse, ribs reddish purple, intercostal areas pale green to whitish. Corollas bicolored, adaxial lip lavender to magenta-purple, adaxial throat very dark purple, abaxial lip or at least central lobe golden yellow, abaxial lip base and palate ridges sparsely red-dotted, 2 adaxial lobes and 2 lateral lobes of abaxial lip with dark maroon purple bands at base and extending into and merging within throat, palate ridges yellow, tube-throat (15–)20–40 mm, limb 10–18 mm diam., bilabiate, lips equal. Anthers (distal pair) sometimes nearly exserted, with apical tufts of short, eglandular hairs. Styles glandular-puberulent. Stigmas usually exserted, lobes subequal. Capsules (2–)3–5.5 mm, indehiscent. 2n = 18.
Phenology: Flowering Apr–Jul.
Habitat: Vernally flooded depressions or swales, ruts, seepage areas on gentle slopes.
Elevation: 600–2000 m.
Diplacus pulchellus is known from Calaveras, Mariposa, and Tuolumne counties.